[unreadable] Real time trans-thoracic volumetric scanning, using 2-D array transducers based on Duke University designs, offers potential to increase the accuracy of cardiac measurements such as ventricular volumes and improve the diagnosis of coronary heart disease. The objective of this proposal is to extend the advances of real time volumetric scanning to transesophageal endoscopes, surgical endoscopes for applications in minimally invasive cardiac surgery. In this research, we will develop new 2D array transducers including cylindrical and hemispherical curvilinear probes operating from 5-10 MHz which produce a panoramic 3-D field of view approaching 1800. We will also develop an intracardiac catheter which combines 3-D ultrasound imaging and endocardial ultrasound thermal ablation system integrated within a single catheter delivery device for applications to the cardiac arrhythmias and interventional cardiology. [unreadable] [unreadable]